1. FIELD OF THE INVENTION
This invention relates to tube couplers and more particularly to quick connect and disconnect tube couplers which establish an effective seal with the end of a tube.
2. BACKGROUND OF THE INVENTION
While many applications for quick acting tube couplings exist, couplers of the present invention have been developed particularly for manufacturing and testing equipment designed to handle fluids. For example, in the manufacture of many refrigeration components those components require testing by the application of fluid under pressure, sometimes preceded by a flushing of the fluid passages of the component and a drying of the flushing liquid in those passages. In manufacturing operations rapid testing is sought. This involves, in the case of fluid tests, a rapidly applied, safe, reliable coupling which can withstand substantial pressures and will function for a large number of operating cycles. Since the flushing, drying and/or testing procedures require only temporary connections, it is essential that the application of the coupling impose minimal distortion on the tube ends to which they are applied in order that those ends can be connected with minimum effort into the system for which the tested component is intended. Further, the tube ends to which connections are to be made are frequently short and smooth walled such that the grip required to maintain the coupling has only a restricted region of the tube wall to which it is to be secured and can tolerate only slight distortion. In the case of thin walled tubes this avoidance of distortion is particularly difficult to achieve.
The sealing functions also must be effective for substantial pressure differentials. Fluid pressures of several hundred pounds per square inch may be required for flushing or testing. In some instances vacuums must be accommodated. Where high volumes of fluid must be passed through the coupling in a minimum time interval the seal should not introduce flow restrictions.
In many applications it is advantageous to maintain fluid pressure on the test lines to the connector and to release that pressure to the device to which the connector is applied as soon as a suitable sealed coupling has been achieved. This expedites the test procedure and simplifies the manual manipulations required at the test station.